A Confirmed Case of SARS-CoV-2 Pneumonia With Negative Routine Reverse Transcriptase-Polymerase Chain Reaction and Virus Variation in Guangzhou, China.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia is a newly recognized disease, and its diagnosis is primarily confirmed by routine reverse transcriptase -polymerase chain reaction (RT-PCR) detection of SARS-CoV-2. METHODS: However, we report a confirmed case of SARS-CoV-2 pneumonia with a negative routine RT-PCR. RESULTS: This case was finally diagnosed by nanopore sequencing combined with antibody of SARS-CoV-2. Simultaneously, the ORF and NP gene variations of SARS-CoV-2 were found. CONCLUSIONS: This case highlighted that false-negative results could be present in routine RT-PCR diagnosis, especially with virus variation. Currently, nanopore pathogen sequencing and antibody detection have been found to be effective in clinical diagnosis.

Epidemiological and clinical characteristics of suspected COVID-19 patients in the isolation ward in Guangzhou, China: a cohort study.

BACKGROUND: Since there are reports of cases of 2019-coronavirus disease (COVID-19) asymptomatic carriers in China recently and fever is one of the main symptoms, we aimed to distinguish COVID-19 cases from other febrile patients with clinical examinations in this study. METHODS: A total of 134 suspected COVID-19 patients in the isolation ward of the First Affiliated Hospital of Guangzhou Medical University were recruited from January 23 to May 23, 2020. We analyze the pathogenic form and clinical characteristics. RESULTS: Among them, pathogens were identified in only 84 patients (62.7%), including 23 (17.1%) with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), 30 (22.3%) with other viruses, 31 (25.0%) with other pathogens and 3 (3.5%) with mixed infections. The commonly observed symptoms of COVID-19 patients were cough, fever, fatigue, and muscle aches, which were significantly different than the symptoms of nonviral infections (P<0.05) but from those of other viral infections (P>0.05). Furthermore, lactate dehydrogenase and the neutrophil/lymphocyte were found significantly high in COVID-19 patients compared to non-COVID-19 patients (P<0.05). The most common manifestations of COVID-19 patients were ground-glass opacities (100%) with or without lung consolidation, however, they also often showed involvement of several lobes of both lungs (P<0.05). Due to the clear differential diagnosis, the overall antibiotic use rate was 35.8% (31/87). CONCLUSIONS: When diagnosing COVID-19, infections with other pathogens should not be ignored. Successful pathogen identification will support accurate treatment.

Longitudinal virological changes and underlying pathogenesis in hospitalized COVID-19 patients in Guangzhou, China.

Prolonged viral RNA shedding and recurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in coronavirus disease 2019 (COVID-19) patients have been reported. However, the clinical outcome and pathogenesis remain unclear. In this study, we recruited 43 laboratory-confirmed COVID-19 patients. We found that prolonged viral RNA shedding or recurrence mainly occurred in severe/critical patients (P<0.05). The average viral shedding time in severe/critical patients was more than 50 days, and up to 100 days in some patients, after symptom onset. However, chest computed tomography gradually improved and complete absorption occurred when SARS-CoV-2 RT-PCR was still positive, but specific antibodies appeared. Furthermore, the viral shedding time significantly decreased when the A1,430G or C12,473T mutation occurred (P<0.01 and FDR<0.01) and increased when G227A occurred (P<0.05 and FDR<0.05). High IL1R1, IL1R2, and TNFRSF21 expression in the host positively correlated with viral shedding time (P<0.05 and false discovery rate <0.05). Prolonged viral RNA shedding often occurs but may not increase disease damage. Prolonged viral RNA shedding is associated with viral mutations and host factors.

Effect of Throat Washings on Detection of 2019 Novel Coronavirus.

The 2019 novel coronavirus was detected in self-collected throat washings. The positive testing rate of throat washing was much higher than that of nasopharyngeal swabs. Throat washing is a promising candidate for 2019-nCoV screening and monitoring due to its noninvasiveness and reliability.

Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis.

The outbreak of the novel coronavirus disease (COVID-19) quickly spread all over China and to more than 20 other countries. Although the virus (severe acute respiratory syndrome coronavirus [SARS-Cov-2]) nucleic acid real-time polymerase chain reaction (PCR) test has become the standard method for diagnosis of SARS-CoV-2 infection, these real-time PCR test kits have many limitations. In addition, high false-negative rates were reported. There is an urgent need for an accurate and rapid test method to quickly identify a large number of infected patients and asymptomatic carriers to prevent virus transmission and assure timely treatment of patients. We have developed a rapid and simple point-of-care lateral flow immunoassay that can detect immunoglobulin M (IgM) and IgG antibodies simultaneously against SARS-CoV-2 virus in human blood within 15 minutes which can detect patients at different infection stages. With this test kit, we carried out clinical studies to validate its clinical efficacy uses. The clinical detection sensitivity and specificity of this test were measured using blood samples collected from 397 PCR confirmed COVID-19 patients and 128 negative patients at eight different clinical sites. The overall testing sensitivity was 88.66% and specificity was 90.63%. In addition, we evaluated clinical diagnosis results obtained from different types of venous and fingerstick blood samples. The results indicated great detection consistency among samples from fingerstick blood, serum and plasma of venous blood. The IgM-IgG combined assay has better utility and sensitivity compared with a single IgM or IgG test. It can be used for the rapid screening of SARS-CoV-2 carriers, symptomatic or asymptomatic, in hospitals, clinics, and test laboratories.